There are many types of one-way roller clutch mechanisms--whether one directional or bi-directional--in use today. These roller clutch mechanisms have particular use in vehicle transfer case applications, although they also have use in many other applications, such as vehicle rear differentials, vehicle and machine transmissions, and other mechanical industrial applications utilizing rotating machinery. In transfer cases, the system provides transfer of torque from the driving wheels to the non-driving wheels whenever the driving wheels experience slippage.
In bi-directional roller clutch mechanisms, the outer surface of the inner race member typically has a wavy cam-type surface, with a roller member being positioned between each of the cams. In these clutch mechanisms, the rollers form a rocking wedge between the driven and drive shafts to drive the driven shaft in a selected direction. Many of these mechanisms are two-way devices and are generally relatively complicated in that some form of spring or shifting mechanism is required to change from a drive in one direction to a drive in the opposite direction.
Also, when the clutch mechanism engages, end loads are applied and the magnitude of the loads can be substantial. Even within normal tolerance ranges, slight differences between roller diameters, cam surfaces and roller travel distances can lead to fatigue of the cage mechanisms and/or premature failure of the cage or clutch mechanism.
A known one-way roller-type clutch mechanism is shown, for example, in co-owned U.S. Pat. No. 4,848,508. Other known clutch mechanisms are disclosed in U.S. Pat. Nos. 5,195,604, 5,307,911, 5,443,147, and 5,542,515.